Which of the following is one of the five basic tastes?

Bitter is one of the five basic tastes, which also include sweet, sour, salty, and umami. The recognition of these tastes allows chefs and culinary professionals to create a balanced flavor profile in their dishes. Bitter flavors are often associated with certain foods like coffee, dark chocolate, and many leafy greens. Understanding bitter as a fundamental taste is crucial for developing complex and balanced recipes since it can enhance other flavors and provide depth to a dish.

The other options reflect different concepts but do not qualify as basic tastes. Piquant refers to a sharp or spicy quality rather than a foundational taste category. Carbonation pertains to the effervescence in beverages, created by the presence of carbon dioxide, which does not constitute a taste itself. Sweetener refers to substances that impart sweetness but is not classified as a basic taste; sweetness is one of the basic tastes rather than the agents that provide it.